1. Field of the Invention
The present invention relates to a jointing holder for an optical module for single-fiber bidirectional communication for securely holding an optical fiber for transmitting multiwavelength light bidirectionally, a semiconductor laser for emitting outgoing light, a photodiode for receiving incoming light, and an optical filter for separating multiplexed wavelengths. The present invention also relates to an optical module for single-fiber bidirectional communication incorporating the jointing holder.
2. Description of the Background Art
In the subscriber loop represented by the FTTH (fiber to the home) system in an optical fiber communications system, signal transmission and reception is mainly performed by a wavelength division multiplexing system using two wavelengths in a 1.3-μm band and a 1.55-μm band transmitted over a single optical fiber.
For such a wavelength division multiplexing system, European Patent EP 0 644 669 A1 and U.S. Pat. No. 5,841,562 have disclosed optical modules for single-fiber bidirectional communication. They are composed of an optical fiber for transmitting multiwavelength light bidirectionally, a semiconductor laser for emitting outgoing light, a photodiode for receiving incoming light, and an optical filter for separating multiplexed wavelengths. These components are securely held by an enclosure through individual fixing members.
Consequently, the conventional optical module for single-fiber bidirectional communication requires individual fixing members for fixing the components to the enclosure. This structure has the following drawbacks: (a) A large number of components make it difficult to miniaturize the module. (b) The positioning of the fixing members to the enclosure is difficult. (c) Dimensional deviation tends to occur at the time of the assembly. (d) An intention to increase the precision leads to a significant increase in the cost.